schap! 2014
Two hours south of Durban the Indian Ocean and the sub-tropical climate define the lush environment around the small village Mzamba in Eastern Cape, South Africa.
Situated in a former homeland, zoned for the Pondo people during the apartheid government and left out from development, the built environment is characterised by round huts made of earth, small self-build houses and gravel roads.
The school building, planned and build by students, accompanied by buildCollectiveNPO and supported in its implementation by a local construction team is the 4th project of the Carinthia University of Applied Science for the client s2arch. As temperatures do not drop lower than 10° C, even on the coldest winter nights of July, primary requirements are protection from strong winds, rain and sun through intelligent air circulation and useable roofed outdoor space.
The classroom unit for the Ithuba Wild Coast School is defined by a large red rammed earth wall between two courtyards and surrounded by a protective wall made out of easily available hollow concrete blocks and ventilation stones offering playful views.
The 21 x 12 meter building compound with classroom, office and sickroom, two water outlets and courtyards, covered circulation on different levels, seating and several entrances, serves as a small village for the learners.
Images and Plans
Technical Description
In a three days workshop at CUAS the essential design elements, such as the rammed earth wall, rain gutter and roof connections were build and tested in scale 1 : 1. The construction of a mock-up does not just give insights on material, detail and proportions but is also testing group dynamics and skills for the actual construction phase of 7 weeks on site.
The roof trusses made of wood are based on self-produced concrete pillars as typical lightweight construction in-filled with window elements or wood and fibre cement panels. The protective outer wall made of cost effective concrete hollow blocks provide a labour-intensive construction method the local team members are experienced in handling.
The idea of using rammed earth derived from local climate, traditional construction methods and the proximity of resources. The clay was purchased from a near by brickyard and an especially red sand harvested only about 5 km from the construction site.
As of time constraints the construction method was balanced into one
8,5 x 0,5 x 2,4m wall element serving identification and appreciation of environmental building techniques. The optimal mixing proportions for the rammed earth wall were established through a series of trials on site. The final mix of 3 : 2 : 1 - three parts of red dessert sand, two parts of yellowish clay and one part of building sand was improved with 5% of white cement for durability without lowering the qualities of the building material.
Because of lack of space and to save time a small lifting platform was built to pour whole wheelbarrows of earth-mix into the 2,4-meter-high framework. The timber used for the elaborate framework enforced with form ties from concrete industry, was reused as roof trusses for the covered outside space.
46 mixes were made by hand with four to five people leading to small discrepancies that caused different shades of orange and red of the individual layers. Two people standing in the framework with traditional earth-floor tools were lifting and ramming the mix until full density was reached.
After two weeks of ramming the framework could be removed to expose the wall which immediately touched and marvelled by students, local construction team, learners and teachers alike.